In fact, galaxies are speeding away from us in all directions like we have the cooties. So if you are in space and look at the daylight side of the Earth it will appear moderately bright. You don't know what it is… oh that's so sweet!". Our daily newsletter arrives just in time for lunch, offering up the day's biggest science news, our latest features, amazing Q&As and insightful interviews. That’s because although starlight gets fainter with distance, a simple calculation shows the fading is cancelled out by the ever-increasing numbers of stars with distance, and should therefore leave space ablaze with light. The stars shine, the planets glow (because light is bouncing off them), gas clouds have light passing through them, that's why they are visible. Robert is a science writer and visiting professor of science at Aston University. You can unsubscribe at any time and we'll never share your details to third parties. Get weekly and/or daily updates delivered to your inbox. So Olbers' instinct was right. Why is space so cold if the sun is so hot? A few hundred thousand years after the Big Bang, when the first light was able to leap out into space, everything, in every direction was as bright as the surface of a star. So, shouldn't the entire sky be as bright as a star, since there's a star in every possible minute direction you could ever look in? The content is provided for information purposes only. Not only do we have this incomprehensibly massive size of our Universe, but the scale of time we're talking about when we do these thought experiments is absolutely boggling. July 24, 2019. The result is a Universe as black as pitch. Shortly after the Big Bang, the entire Universe was hot and dense, like the core of a star. The light is still there, but it does not scatter into blue sky like it does with Earth's atmosphere. For more information about how to do this, and how Immediate Media Company Limited (publisher of Science Focus) holds your personal information, please see our privacy policy. Just the floating part, not the peeing into a vacuum hose or eating that funky "ice cream" from foil bags part. If you look in every direction, you're seeing a spot as bright as a star, it's just that the expansion of the Universe stretched out the wavelengths so that the light is invisible to our eyes. We live in a universe of extremes. Space looks dark, because it is mostly a near-perfect vacuum. And so, PARADOX SOLVED! Clearly, there’s something wrong with the simple calculation, and a big clue about what it is came in the 1920s when astronomers discovered that the Universe is expanding after exploding from a Big Bang billions of years ago. In space, because there is nothing to scatter or reflect the light, it is black. Save 52% when you subscribe to BBC Science Focus Magazine. Isaiah 13:10 - For the stars of heaven and their constellationsWill not flash forth their light;The sun will be dark when it risesAnd the moon will not shed its light. Discover our latest special editions covering a range of fascinating topics from the latest scientific discoveries to the big ideas explained. We don't see stars in every direction because many of the stars haven't been around long enough for their light to get to us. Did you come up with Olbers' Paradox too? Looking up into the night sky, one has to wonder why the Universe is primarily black. PLUS a free mini-magazine for you to download and keep. Dave - The Sun is incredibly hot, but the Sun is not throughout the whole of space. It’s perplexed many astronomers since the time of Sir Edmond Halley, of comet fame, in the 17th century. Has there ever been a planet-planet eclipse (i.e., observed from Earth)? Your opinions are important to us. The paradox goes like this: if the Universe is infinite, static and has existed forever, then everywhere you look should eventually hit a star. So, PARADOX SOLVED! Space is dark because there's nothing there. So by proposing this paradox, Olbers knew the Universe couldn't be infinite, static and timeless. Our Universe has proven to not be static or timeless. Our experiences tell us this isn't the case. So if you look at the Sun lots of light arrives in your eye and the Sun appears bright. Boiling into space. July 24, 2019 This is Cosmic Microwave Background Radiation, and you guessed it, we can detect it in every direction we can look in. Here let me give you a little coaching, you'll start your conversation at the party with "So, the other day, I was contemplating Olbers' Paradox… Oh what's that? It could be a couple of these, but not all three. This is one of those ‘silly’ questions, which has an answer that’s anything but. This document is subject to copyright. It even be infinite, which is much bigger than huge. By Gideon Lichfield. Already have an account with us? Light shines out from the Sun in straight lines. It’s perplexed many astronomers since the time of Sir Edmond Halley, of comet fame, in the 17th century. Look out for your Lunchtime Genius newsletter in your inbox soon.